Food Consumption, Ingestion, and Selectivity of Golden Pompano Trachinotus ovatus Larvae Under Various Rotifer Densities

In this chapter, rotifer densities, food selectivity, and color preference during the rotifer feeding stage of Trachinotus ovatus were reviewed. T. ovatus larvae were reared under four rotifer densities (1, 10, 20, and 40 rotifers mL−1), two types of live preys (rotifer and copepod nauplii), four colors of rotifer (blue, red, green, and purple), and five tank colors (black, green, white, pink, and dark red). The study was conducted between 1 day post hatching (DPH) and 5 DPH. In the feeding density of 20 rotifers mL−1, the specific growth rate and survival rate were maximum. In terms of food ingestion, both 10 rotifers mL−1 and 20 rotifers mL−1 at 5 DPH and 9 DPH are significantly higher than other rotifer densities (P < 0.05), but there was no significant difference in each density at 7 DPH (P > 0.05). The rotifer consumption was no significant difference in each density at 7 DPH (P > 0.05), but the rotifer utilization efficiency had a significant difference and decreased with the increase of rotifer density (P < 0.05). The rotifer density of 1 rotifer mL⁻¹ not only reduced food ingestion during the early stage but also delayed diet switch from rotifer to copepod nauplii. Dark tank background colors such as black and dark red could increase the food ingestion of larvae. Meanwhile, when fed with green rotifers, the food ingestion of larvae is significantly higher than that of other colors (P < 0.05). In the present study, the rearing of larval T. ovatus is suggested using dark wall color tanks with a feeding density of 10–20 rotifers mL⁻¹ during the initial feeding stage. This chapter proposes a management protocol to use suitable type and quantity of live food to feed T. ovatus larvae in a hatchery rearing condition, which could be applicable to the rearing of larval fish in other marine fish species.